Publications by authors named "Hans-Ulrich Graber"

Article Synopsis
  • The study assessed the prevalence of Staphylococcus aureus subclinical mastitis in lactating cows, finding it to be 5.4%, with higher risks on small and medium-sized farms.
  • The research identified 44 S. aureus genotypes, including 15 new ones, and noted differences in gene frequency related to adherence and enterotoxin production between new and known genotypes.
  • Methicillin-resistant S. aureus (MRSA) strains were more common on larger farms, highlighting the effectiveness of molecular techniques for understanding and managing staphylococcal infections in dairy cattle.
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Healthy, untreated cows of nine dairy herds from the Swiss Canton Tessin were analyzed three times within one year to identify the most abundant species of the intramammary bacteriome. Aseptically collected milk samples were cultured and bacteria identified using MALDI-TOF. Of 256 cows analyzed, 96% were bacteriologically positive and 80% of the 1,024 quarters were positive for at least one bacterial species.

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In dairy herds managements, mastitis is the leading cause of economic losses. One of the most important pathogens responsible for intra-mammary infections is . The genetic properties of have a strong influence on its pathogenicity and contagiousness.

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Abstract: To reduce the number of cheese with potential Staphylococcus aureus contamination reaching consumers, European legislation has stipulated that all cheese must be tested for coagulase-positive staphylococci (CPS) at the point in production when numbers are expected to be highest. When CPS counts exceed 105 CFU/mL, staphylococcal enterotoxin (SE) tests must be conducted. When SE tests are positive, the cheese must be destroyed.

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is recognized worldwide as one of the major agents of dairy cow intra-mammary infections. This microorganism can express a wide spectrum of pathogenic factors used to attach, colonize, invade and infect the host. The present study evaluated 120 isolates from eight different countries that were genotyped by RS-PCR and investigated for 26 different virulence factors to increase the knowledge on the circulating genetic lineages among the cow population with mastitis.

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Quantitative microbial risk assessment (QMRA) models are extensively applied to inform management of a broad range of food safety risks. Inevitably, QMRA modeling involves an element of simplification of the biological process of interest. Two features that are frequently simplified or disregarded are the pathogenicity of multiple strains of a single pathogen and consumer behavior at the household level.

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